When I first published 3Deep in 2016, I intended to release the setting-neutral rules and follow it up quickly with splatbooks that tweaked the game to fit each setting and genre.
I produced two books, one of which I wrote myself, and one was an adaption of No GM's Sky by Todd Zircher. Ironically, supers was supposed to be the first book. My roleplaying education started with D&D B/X and then moved through Champions, Traveller, Runequest, and Rolemaster, and the real eye-opener was when we started roleplaying Steve Jackson's Car Wars. That told me that any game that had a character could be roleplayed. All you needed were some rules for conflict resolution. If you are familiar with 3Deep, you may have noticed a healthy dose of the original Car Wars in those rules as well as some Champions and Traveller. Our early influences stay with us, or mine did.
This book takes the core of 3Deep and introduces rule tweaks and suggestions to bend it to the Supers genre.